On Di, 2019-04-30 at 15:02 +0200, Andrey Konovalov wrote: > On Tue, Apr 30, 2019 at 2:58 PM Oliver Neukum <oneukum@xxxxxxxx> wrote: > > > > On Fr, 2019-04-12 at 04:36 -0700, syzbot wrote: > > > Hello, > > > > > > syzbot found the following crash on: > > > > > > HEAD commit: 9a33b369 usb-fuzzer: main usb gadget fuzzer driver > > > git tree: https://github.com/google/kasan/tree/usb-fuzzer > > > console output: https://syzkaller.appspot.com/x/log.txt?x=174ce2e3200000 > > > kernel config: https://syzkaller.appspot.com/x/.config?x=23e37f59d94ddd15 > > > dashboard link: https://syzkaller.appspot.com/bug?extid=35f04d136fc975a70da4 > > > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=138150f3200000 > > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1290c22d200000 > > > > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > > > Reported-by: syzbot+35f04d136fc975a70da4@xxxxxxxxxxxxxxxxxxxxxxxxx > > > > > > usb 6-1: USB disconnect, device number 2 > > > rio500 3-1:0.110: USB Rio disconnected. > > > usb 4-1: USB disconnect, device number 2 > > > ================================================================== > > > usb 1-1: USB disconnect, device number 2 > > > BUG: KASAN: double-free or invalid-free in slab_free mm/slub.c:3003 [inline] > > > BUG: KASAN: double-free or invalid-free in kfree+0xce/0x290 mm/slub.c:3958 > > > usb 2-1: USB disconnect, device number 2 > > > > > > > Try as I might, I don't understand this. I can see a memory leak, > > but not a double free. > > I took a look at this some time ago, and I was under the impression > that this driver doesn't handle multiple devices being connected at > the same time well. You are right. A global variable is used. A fix is being worked on. Regards Oliver
